Modification of cellulosic textile materials with divinyl sulfone precursors

ABSTRACT

ACTIVE HYDROGEN CONTAINING POLYMERS ARE MODIFIED IN THE PRESENCE OF AN ALKALINE CATALYST WITH DIVINYL SULFONE PRECURSORS.

United States Patent Ofice 3,574,521 MODIFICATION OF CELLULOSIC TEXTILEMATERIALS WITH DIVINYL SULFONE PRECURSORS Giuliana C. Tesoro, DobbsFerry, N.Y., and Paul I. Linden, North Arlington, N.J., assignors to J.P. Stevens & Co., Inc., New York, NY.

No Drawing. Continuation-impart of applications Ser. No. 826,133, July10, 1959, and Ser. No. 51,778, Aug. 25, 1960. This application Jan. 3,1961, Ser. No. 79,988

Int. Cl. D06m 13/28; C08b 11/04, 19/06 US. Cl. 8--116.2 11 ClaimsABSTRACT OF THE DISCLOSURE Active hydrogen containing polymers aremodified in the presence of an alkaline catalyst with divinyl sulfoneprecursors.

This application is a continuation in part of application Ser. No.826,133 filed July 10, 1959, now abandoned, and application Ser. No.51,778 filed Aug. 25, 1960, now US. Pat. No. 3,000,762.

The present invention relates to novel processes by which polymerscontaining active hydrogen atoms are crosslinked with polyfunctionalsulfone compounds to increase their water resistance and dimensionalstability and the novel products resulting therefrom.

Among the polymers contemplated are natural polymers such as cellulose,proteins, starches and the like, and synthetic polymers such aspolyvinyl alcohol, partially saponified polyvinyl esters and the like.The polymers can be nonfiber forming (e.g. starch, soluble cellulose,polyvinyl alcohol resin and the like), or they can be fiber formingpolymers (e.g. cotton cellulose, regenerated cellulose, wool keratin,polyvinyl alcohol fiber and the like). In the case of fiber formingpolymers containing active hydrogens, the textile structuresmanufactured from them are particularly suitable as raw materials forthe processes of the invention since the modification of textilematerials such as fibers, yarns, filaments, woven fabrics, knittedfabrics and non-woven fabrics with polyfunctional reagents is known toresult in highly desirable properties. In addition to increasing waterresistance and dimensional stability, the reaction of textile materialswith crosslinking reagents also increases resilience. The modificationof textile materials in fabric form and in fiat condition increasescrease recovery and fiat drying properties, and the treated fabrics thusexhibit properties which greatly increase their usefulness. In addition,fabrics treated in creased or pleated condition, will permanently retainthe creases or pleats imparted in the course of the treatment. Thus flatdrying properties and permanent creases which are retained in the courseof laundering and dry cleaning can be imparted to fabrics by theprocesses of our invention.

Many processes are known by which similar objectives can be achieved,but all known processes have serious, shortcomings. Generally speaking,known processes for the modification of fibrous polymers containingactive hydrogen and more particularly of the textile materials made fromthem, fall into two categories: (1) treatment with thermosetting resinswhich are reacted by baking or curing in presence of acidic or acidgenerating catalysts and (2) treatment with alkylating agents inpresence of concentrated alkaline solutions which swell the fibersgreatly. Processes in the first group usually involve the use ofnitrogenous reagents containing formaldehyde, and cause objectionablepersistent odors in the processing, storage and use of the fabrics.Furthermore, the chemical bonds formed in the reaction with the polymerare suscep- 3,574,521 Patented Apr. 13, 1971 tible to hydrolytic attackand to retention of chlorine from bleaching solutions, so that thetreatment is often removed, altered and impaired in the course of normallaundering procedures. Processes in the second group also have seriousshortcomings. The necessity for employing concentrated alkalinesolutions makes the processes unsuitable for use on alkali-sensitivepolymers (e.g. regenerated cellulose). Furthermore, due to the strongswelling action of the alkaline solution, the reaction takes place whilethe polymer is in a highly swollen condition; and in the case of textilematerials, this leads to improved resilience in the wet state only, withdry resilience remaining unchanged or even being impaired.

In an elfort to overcome the disadvantages recited above for knowntreatments, the use of divinyl sulfone as a reagent has been suggested.This reagent reacts readily at room temperature with compoundscontaining active hydrogen in the presence of catalytic amounts ofalkaline compounds. It is an effective crosslinking agent for polymericcompounds containing active hydrogen generally, and for fiber formingpolymers in particular. However, its use on an industrial scale has notbeen possible since the physico-chemical and physiological properties ofthe reagent constitute an insurmountable barrier to its use inconventional installations.

Divinyl sulfone is an extremely toxic chemical, orally and by absorptionthrough the skin. It is a powerful lachrymator and vesicant. It is aliquid of relatively high vapor pressure, and therefore difiicult tohandle (as for example in weighing). At alkaline pH (9.0 and above), itreacts readily with water so that aqueous alkaline solutions of divinylsulfone have very limited stability.

The conversion of divinyl sulfone to certain water soluble derivativeswhich liberate divinyl sulfone in the presence of alkaline reagents cansuccessfully overcome the difiiculties associated with the use ofdivinyl sulfone itself, but it is essential to react the compounds undercarefully selected conditions, since by improper choice of reactionconditions the problems mentioned above for the reaction of divinylsulfone will be retained, and in some cases, even aggravated.

Accordingly it is an object of this invention to provide a process forcrosslinking polymers containing active hydrogen atoms withpolyfunctional sulfone compounds to increase the water resistance anddimensional stability of said polymers. It is a further object of thisinvention to provide a process for crosslinking polymers containingactive hydrogen atoms with polyfunctional sulfone compounds whereby theshortcomings noted above for existing processes are substantiallyeliminated.

It is a further object of this invention to provide a process forcrosslinking polymers containing active hydrogen atoms withpolyfunctional sulfone compounds under moderate reaction conditionswhereby the water resistance and dimensional stability of said polymersare increased.

A further object of this invention is to provide novel polymericmaterials which are made by crosslinking polymers containing activehydrogen atoms with polyfunctional sulfone compounds under moderatereaction conditions.

Further objects of this invention will be apparent from.

novel products resulting from this process and which are characterizedby having improved water resistance and dimensional stability.

The divinyl sulfone derivatives contemplated in this invention can berepresented by the general Formula I CH-CH-Y fil RIII where R, R, R", R'are selected from the group consisting of hydrogen and lower alkyl, andY represents a polar residue derived from a reagent of weak nucleophiliccharacter such as the cation of a weak base (e.g. pyridinium,quinolinium and the like) and the anion of a strong acid (e.g. SSO Na orthiosulfate, OSO Na or sulfate and the like). Nucleophilic character isdefined as the tendency to donate electrons or share them with a foreignnucleus (Gilman, Oragnic Chemistry, second edition, vol. II, p. 1859).More specifically, Y can be derived from a tertiary amine having anionization constant lower than about 10 or it can be derived from aninorganic polybasic acid having an ionization constant higher than aboutl" or from an organic or organically substituted inorganic acid:

The following are specific examples of compounds suitable for theprocess of the invention, and included among the compounds of Formula I,

(II) CHz-CHzOSOaM CH2CH2OSOaM where M is selected from the groupconsisting of alkali metal and ammonium,

(III) CHzCHzSSOaM CHzCHzSSOaM where M has the same meaning as in FormulaII.

(IV) CHzCHzOCOCHa CHzCHzO C 0 CH3 CHzCHfifCsHs 0 HzCHzIlI C 5H5 where Xis a halogen.

CHzCHgN-CHzCoHa CHa S O 2 2X- CH3 CHzCHzN--CHzCsH5 where X is a halogen.

(VII) CHz-CEz CHzCHr- O CHz-CH: S 02 CHz-CHZ CH2CH2- O CHz-Cfiz and itssalts.

Specific examples of alkaline materials suitable for the process of theinvention are the phosphates, carbonates, hydroxides, alkoxides andsilicates of alkali metals; the quaternary ammonium hydroxides, andgenerally com- 4 pounds which are strong bases, but are not capable ofreacting with divinyl sulfone. The alkali hydroxides are preferredbases, since they are readily available, easily soluble and economical.

The following important conditions must be fulfilled when thesecompounds are reacted with polymers containing active hydrogen and moreparticularly with textile materials such as fabrics:

(1) The treatment of textile materials, and particularly fabrics, isgenerally carried out by impregnation from aqueous solutions which mustbe stable, since they are normally used over a prolonged period of timeeither continuously or at intervals. In the process of this invention,the fabric is contacted with a stable, aqueous, neutral solution of thesulfone and is treated with the alkaline component of the reactionsystem in a separate step. These steps can be carried out in anysequence, with or without intermediate drying, but the preferredprocedure consists of impregnation with the sulfone solution, followedby drying and by impregnation with the alkaline material. If the alkaliis added to the sulfone solution in order to carry out the treatment ofthe fabric in a single step, the,

solution immediately begins to liberate lachrymatory fumes and becomesvery difiicult to handle. Furthermore, within a short time, waterinsoluble by-products begin to form within the solution which soonbecomes ineffective for the desired fabric treatment. Accordingly thepolymer should not be simultaneously contacted by the sulfone and alkalibut contact should be sequentially. As noted above the polymer can firstbe contacted by the sulfone followed by the alkali or vice versa, but ineither instance the polymer should be present during contact of thesulfone and alkali so that the divinyl sulfone formed can react with thepolymer as fast as it is formed, thereby avoiding the liberation ofnoxious fumes and the formation of undesirable by-products.

(2) When soluble polymers are treated (as distinguished from textilestructures), the two-step procedure outlined above is not alwaysfeasible, and the following alternate condition should be fulfilled. Thepolymer (e.g. starch) is intimately mixed with the neutral, stablesulfone solution. The alkaline material is then added gradually, so thatreaction takes place as rapidly as the reagent is formed. If the alkaliis added to the sulfone solution prior to addition of the polymer, sidereactions begin to set in immediately, and the yield in the reaction ofthe sulfone with the polymer is severely impaired.

(3) The reaction between the sulfone, alkali and polymer shouldpreferably be allowed to proceed at moderate temperatures and in thepresence of water or an inert solvent. The use of elevated temperaturesin the presence of alkaline materials causes severe discoloration anddamage of the treated polymers, and furthermore, often causesdecomposition of the sulfone compound, with formation of undesirable andunreactive by-products. For example, heating of the compound of FormulaIII with a polymer in the presence of alkaline material results inextensive decomposition of the reagent, poor yields of treated polymer,and an unsightly brown discoloration which cannot be eliminated bycommon bleaching procedures. The presence of Water or solvent isadvantageous, and actually essential in some instances. The water orsuitable solvent carries the reagent into the polymer and allows thereaction to take place at room temperature. If the water is removed, thereaction can no longer take place unless the system is heated; andheating is undesirable for the reasons given above.

In summary then, the process of the present invention consists ofcontacting the sulfone compounds of Formula I with polymers containingactive hydrogen, in the presence of an alkali reaction medium which cancontain water or other suitable solvent, at a temperature below theboiling point of the solvent employed, and by a se quence of steps whichinsures solution stability and uniformity of treatment over prolongedperiods of time.

By employing the process of this invention for the h treatment oftextile fabrics such as cellulosic fabrics, products of greatly improvedproperties can be obtained. Crease recovery properties and wash/weareffects are greatly enhanced, pleats and mechanical effects areretained, excellent dimensional stability is achieved. According to theprocess of this invention, the fixation of such non-cellulosicstiffening or sizing agents as starch, gelatine, and polyvinyl alcoholcan also be greatly improved. All these properties are substantiallypermanent to laundering, and impervious to chlorine bleaches, scouringprocesses and other cleaning procedures.

For the treatment of fabrics, the concentration of sulfone employed canbe varied widely, depending on the extent of modification desired.Concentrations between and 30% based on the weight of polymer reactantcan be employed.

The amount of the alkaline compound should be at least equivalent to theamount of sulfone present on or in the polymer, and can be much greater.When a large excess of alkali is employed, the reaction is almostinstantaneous and caution must be exercised to limit the reaction timeto a maximum of about 3 hours and preferably to about 30 minutes, sinceprolonged standing (even at room temperature) of the treated polymer incontact with a large excess of strong base can cause the reaction to bereversed, and the yield to decrease. When essentially stoichiometricamounts of the sulfone and alkali are employed, the reaction time is notcritical, and can be varied from minutes to 24 hours without significantchange in the reaction yield or in the properties of the treatedpolymer. Thus, the reaction time at room temperature can be varied froma few seconds to many hours, depending on the basic strength and amountof the alkaline component. The required reaction time decreases withincreasing base strength and with increasing amounts of base.

The following examples are illustrative of the present inventionalthough it will be understood that these examples are not to beconstrued as limitative of the scope of the invention.

EXAMPLE I A plain weave cotton fabric (commonly referred to as 80 x 80print cloth) was impregnated with an aqueous solution containing 280parts of the product CHzCHrS S Oa a CH2CH2S S OaNa in 720 parts ofwater, and the excess solution was removed by passing through squeezerolls set at such pressure that the wet pickup was approximately 100%.The impregnated fabric was dried at 3540 C. The dried fabric containingthe sulfone was somewhat stiff. It was then impregnated with an aqueoussolution containing 80 parts of sodium hydroxide in 920 parts of water.The amount of sodium hydroxide solution picked up by the fabric wasapproximately 58%, based on the original fabric weight. Thus, the amountof sodium hydroxide present on the fabric during the reaction was 4.7%based on the original fabric weight. After the second padding operation,the fabric was allowed to stand at room temperature in the wet state forminutes, then thoroughly washed with Triton X-100 (a non-ionic detergentmanufactured by the Rohm & Haas Chemical Co.) solution and dried. Thecotton fabric thus treated was soft to the touch, and exhibited greatlyimproved wet crease recovery and dry crease recovery over untreatedfabric.

When this fabric was washed by usual laundering procedures it exhibitedan outstanding ability to dry fiat and wrinkle-free without ironing. Anuntreated fabric washed and dried simultaneously had a wrinkled andunsightly appearance. This property of drying smooth and flat withoutrequiring ironing is a result of the treatment described in thisexample.

EXAMPLE II A viscose rayon gabardine fabric was treated with a 25%aqueous solution of the product used in Example I. The wet pickup wasapproximately The fabric was dried at 50 to 60 C., then treated with a9% solution of potassium hydroxide, rolled smoothly and allowed to standwet at room temperature for 30 minutes. The fabric was thereafterneutralized with dilute acetic acid, Washed and dried. The followingtable shows the recovery properties of the treated fabric and of theuntreated control fabric. The Crease Recovery was determined [by themethod described in the Technical Manual of the Association of TextileChemists and Colorists 1959 edition, vol. 35, pp. 171-173 (TentativeTest Method 67-1957) and is expressed as the sum of values obtained inwarp and filling directions. The wash/wear properties were determined bythe method described in the same publication (p. 154-156) and areexpressed by the recommended indices.

TABLE I Crease recovery Wash/wear rating 1 after 5 (W+F) launderings at140 F.

Viscosegabardine Wet Dry Line dried Tumble dried Untreated 187 202 I. Ol. 5 Treated (Ex. 2) 255 225 4. 0 4.5

1 Igatings from 1.0 (worst appearance) to 5.0 (best appearance Inaddition, while the untreated fabric had a shrinkage of 7.0% (warp) and5.0% (filling) after 5 launderings, the treated fabric did not show anymeasurable shrinkage.

EXAMPLE HI The procedure of Example I was repeated, except that the bis(,B-pyridiniurrunethyl) sulfone dichloride CH2CHZIEC5H5 was used inplace of the thiosulfate compound for the treatment of the same cottonfabric.

The properties of the treated fabric are illustrated by the followingcrease recovery values, determined by the methods indicated above.

TABLE II Crease recovery (W+F) 80 x 80 cotton Wet Dry Untreated 144Treated (Ex. III), Sample A 314 231 Treated (Ex. III), Sample B 298 245EXAMPLE IV A cotton fabric was treated with a 25% solution of thedisodium salt of the bis-sulfuric acid ester of bis-beta hydroxyethylsulfone CHzCHzOSOsNa CHzCHzOSOaNfl that the properties imparted by ourTable III shows treatment are substantially permanent to washing.

EXAMPLE V Forty-four grams of a 10% aqueous solution of a partiallysaponified polyvinyl acetate (containing about 40% residual acetateproduct marketed as Gelvatol 40-10 by the Shawinigan Resin Corp.) weremixed with 32 grams of a 25% solution of the sulfone compound CHCHzSSOQNa CHgCHzSSOaNB A clear solution resulted. Upon adding 17.6 gramsof a 25 aqueous solution of sodium hydroxide, an insoluble polymerimmediately precipitated. This was washed with dilute acetic acid, thenwith water and dried. The polymer was insoluble in boiling water.

EXAMPLE VI EXAMPLE VII One hundred-fifty grams of corn starch (PearlCorn Starch-Clinton Industries, Inc.) were stirred with a solutioncontaining 200 grams of water, 10 grams of a 25 solution of the sulfoneof Example 5 until a homogeneous slurry was formed. This slurry was thentreated with 100 grams of 3% sodium hydroxide solution, and the mixturewas allowed to stand at room temperature. At the end of 1 hour, thesolid was filtered, washed with dilute acetic acid and water.

A test portion of the solid product (1 gram) was suspended in grams ofwater and the water was brought to a boil. The modified starch productswelled slightly, while the untreated starch formed a thick gelatinousmass when tested by the same procedure.

EXAMPLE VIII Samples of yarn manufactured from unmodified polyvinylalcohol fiber (non-heat treated, yarn size /1) were impregnated with anaqueous solution containing 250 grams per liter of the sulfone compoundCHgCHzSSOaNa omoHgssmNa The yarn was passed through the squeeze rolls ofa laboratory padder, adjusting the pressure of the rolls so as to give awet pickup of about 75%. The uptake of sulfone was thus about 18 gramsper 100 grams of yarn. The yarn so treated was dried, then passedthrough a 10% potassium hydroxide solution, squeezed through the rollsof the padder and allowed to stand at room temperature for minutes. Itwas then washed in dilute acetic acid and water, and dried. The yarn sotreated is insoluble in boiling water, while the untreated yarn was 8gradually dissolved when immersed in water at 70- C.

EXAMPLE IX Samples of cotton fabric were treated with solutions of thefollowing composition, passed through the rolls of a laboratory padderset to give about 70% wet pickup, and dried:

Sample Solution a 7.7% Kosol starch (cold water sol. starcha product ofthe National Starch and Chemical 00.).

b 7.7% Kosol starch plus 1.5% sulfone of Example 3.

c 7.7% Kosol starch plus 4.6% sulfone of Example 3.

d 7.7% Kosol starch plus 4.6% of a 25% solution of the sulfone ofExample 5.

e 7.7% Kosol starch plus 9.2% of a 25% solution of the sulfone ofExample 5.

f 6.2% polyvinyl alcohol resin (Gelvatol 1-90-a product of theShawinigan Resin Corp).

g 6.2% polyvinyl alcohol (Gelvatol 1-90) plus 6.2% of a 25% solution ofthe sulfone of Example 5.

h 6.2% polyvinyl alcohol (Gelvatol 1-90) plus 23.1% of the sulfone ofExample 3.

After drying, the samples were treated w1th a 10% solution of sodiumhydroxide, passed through the squeeze rolls of a laboratory padder andallowed to stand at room temperature for 1 hour. After neutralizingwashing and drying, all samples exhibit varying degrees of body andstiffness. It will be noted that samples (a) treated with starch only,and (f) treated with polyvinyl alcohol only, lose their stiffness afterone machine laundering at F., while the hand, feel and stillness of allother samples remained essentially unchanged through 5 or more machinelaunderings at 140 F. These experiments demonstrate the insolubilizationof starch and polyvinyl alcohol sizing materials in situ by the processof our invention.

Other fabrics besides cotton can be treated in this manner. For example,fabrics manufactured from regenerated cellulose, polyamide, polyesterand acrylic fibers can be so treated if a stiff finish which is durableto laundering is desired.

While the illustrative embodiments of the invention have been describedhereinbefore with particularity, it will be understood that variousother modifications will be apparent to and can readily be made by thoseskilled in the art without departing from the scope and spirit of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the description set forth herein butrather that the claims be construed as encompassing all the features ofpatentable novelty which reside in tre present invention including allfeatures which would be treated as equivalents thereof by those skilledin the art to which the invention pertains.

We claim:

1. A process for treating a cellulosic textile material containing freehydroxyl groups in a cellulose molecule which comprises treating saidcellulosic material with a sulfone in the presence of an alkalinecompound and solvent, said sulfone having the structure selected fromthe group consisting of:

CHzCHzO CO CH:

CHzCHzO CO CH:

and

wherein R, R, R" and R are selected from the group consisting ofhydrogen and lower alkyl; R R and R are selected from the groupconsisting of alkyl, aryl, and alkaryl substituents of a tertiary aminehaving an ionization constant lower than about l- X is a negativelycharged ion derived from an acid selected from the group consisting ofhalogen, sulfuric, nitric, methanesulfonic and benzenesulfonic acids,the alkaline compound being in sufiicient quantity to neutralize asubstantial portion of the acidic component formed from said polarresidue, the solvent being present during reaction to produce acrosslinked cellulosic molecule of changed properties, said processbeing carried out in the absence of a noncellulosic polymer containinghydroxy groups capable of reacting with said sulfone.

2. The process of claim 1 in which the cellulosic material is contactedfirst with the sulfone and then with the alkaline compounds.

3. The process of claim 1 in which the cellulosic material is contactedfirst with the alkaline compound and then with the sulfone.

4. The process of claim 1 in which the cellulosic material is acellulosic fabric.

5. The process of claim 1 wherein the temperature of the reactionbetween the sulfone and the cellulose molecule is below the boilingpoint of the solvent and the period of time for the reaction ranges froma few seconds to about 24 hours.

6. The process of claim 1 wherein the sulfone is CHzCHzO C O CH:

CHzCHzOCO CH:

7. The process as defined in claim 1 which is carried out byimpregnating the textile with the solution of the sulfone, drying thetextile and impregnating the dried textile with a solution of thealkaline compound and allowing the impregnated textile to stand in thewet state.

8. The process as defined in claim 1 which is carried out byimpregnating the textile with a solution of the sulfone, impregnatingthe textile with a solution of the alkaline compound and allowing theimpregnated textile to stand in the wet state.

9. A process as defined in claim 1 which is carried out by impregnatingthe textile with the solution of the alkaline compound, drying thetextile and impregnating the dried textile with a solution of thesulfone and allowing the impregnated textile to stand in the Wet state.

10. The process as defined in claim 1 which is carried out byimpregnating the textile with a solution containing the alkalinecompound, impregnating the textile with a solution of the sulfone andallowing the impregnated textile to stand in the wet state.

11. The product of the reaction of a sulfone with a cellulosic textilematerial according to the process as defined in claim 1.

References Cited UNITED STATES PATENTS 3,033,682 9/1961 Tesoro117-139.5R 2,985,501 5/1961 Gagarine 8-Sulfone 2,524,399 10/1950 Schoeneet al. 8Sulfone 2,474,808 7/1949 Schoene 260-6O7 2,670,265 2/ 1954 Heynaet al. 1 8-120 2,539,704 1/1951 Schoene et al. 8116X 2,955,016 10/1960Moore 8128 2,524,400 10/1950 Schoene et a1 8Sulfone 3,031,435 4/1962Tesoro 8-Sulfone OTHER REFERENCES Stahmann et al., I. of OrganicChemistry, Mar. 22, 1946, Pp- 719-735.

GEORGE -F. LESMES, Primary Examiner J. CANNON, Assistant Examiner US.Cl. X.R.

